All functions get a 404 error

Hi, I am new with Netlify and I am using a free account. I am having a problem that seems to me to be very basic, but I still cant solve it.

I am trying to create a minimal site by dragging & dropping my directory (not using Git). The index.html works. This is my netlify.toml file:

[build]
  publish = "/"
  functions = "functions"

I have created some functions in the functions directory but are all unreachable.
So, these work:
https://mysite.netlify.app &
https://mysite.netlify.app/otherfile.html

but any function (e.g. functions/test-function.js) I call like this:
https://mysite.netlify.app/.netlify/functions/test-function
is unreachable and i get a “Page not found”.

Is there a setting I am missing? Any help is welcome…

Functions don’t work in drag-n-drop.

wow, so simple, thank you. I show some tutorials that advised creating the functions folder and dropping the whole site.

So, only through github or similar?

You can use Netlify CLI or GitHub. If you use CLI, you need to use the command netlify deploy --build --prod to match the result of what you get from a deploy via GitHub.

thanks a lot, I appreciate your help